A “filter” is any circuit, logic or other construct that separates data, signals, or other material in accordance with specified criteria. In electrical engineering, for example, a “bandpass” filter is any device or logic that removes components of an input signal that lie outside of a particular frequency range. A “notch” filter, on the other hand, removes only certain frequencies from the input signal, while generally leaving the remaining frequencies intact. Similarly, a “low pass filter” can be used to remove high frequency components from an input signal, and a “high pass filter” can be used to remove low frequency components.
Filters can be implemented in many different ways. Traditional analog filters can be constructed from conventional resistor-capacitor circuitry, for example, to pass or block electrical signals having certain frequencies. More recently, signal filters have been implemented digitally, using a digital signal processor or programmable array circuit of any sort. These digital filters can often be configured and implemented in software, thereby allowing for a very high level of customization and for relative ease in implementation. Although digital filtering techniques have become very sophisticated, it is nevertheless desirable to improve their performance without significantly increasing complexity.
Accordingly, it is desirable to provide systems and techniques for effectively and efficiently implementing a digital filtering technique. Other desirable features and characteristics will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.